Hollow rivet.



E. M. COBB.

HOLLOW RIVET.

APPLICATION FILED APR. 18, 1912. RENEWED AUG. 22, 1914.

1,130,962, Patnted Mar. 9, 1915.

THE NORRIS PETERS CQ, PHOTOJJTHQ, WASHINGION, D C.

UNITED STATES P TENT orrion.

ELMER M. COBB, 0F PORTLAND, MAINE, ASSIGNQR TO SOUTHWORTI-I IILAGIEIINIE. COMPANY, OF PORTLAND, MAINE, 'A QQRPGRATION'OF MAINE.

HOLLOW nrvn'r.

Specification of Letters Patent.

Patented Mar. 9, 1915,

Application filed April 18, 1912, Serial No. 691,764. Renewed August 22, 1914. Serial No. 858,129.

To all whom it may concern 7 Be it known that I, ELMER M. COBB, of

been formed up from a blank composed of radial strips projecting out from an integral center, these strips or arms being folded down to form the cylindrical body of the shank and the head or flange. Rivets of this character or those formed integral with a solid end cannot be upset by the appli- V cation of pressure at the two ends without liability of the walls of the shank crushing inward and thus spoiling the rivet. Accordingly it has been customary to provide a device for upsetting these rivets which contains a retracting mandrel to be inserted into the shank of the rivet through the head.

The object of my invention is to design a hollow solid ended rivet which may be upset and flattened out without the insertion of a mandrel by simply being crushed between a follower and an anvil and which may if desired, be made with both ends closed.

I carry out the above objects by means.

of the rivet hereinafter described and shown.

My invention will best be understood by reference to the accompanying drawing, which shows a hollow rivet constructed according to my invention.

In the drawing, Figure 1 represents the blank for forming the shank and portion of the head, Fig. 2 is a side elevation of the rivet without the cap, Fig. 3 is part elevation and part section of the rivet in position before being crushed or upset, Fig. 4 is the same after the rivet is upset, Fig. 5 is an end view showing the expanded portion, Fig. 6 is a side elevation of a modification, and Fig. 7 is a section on the line -mmofFig.6.

The peculiar feature of my rivet is that the hollow shank has a solid end and is made up of a series of longitudinal sections forming a tapering end which makes an angle with the body of the rivet. The longitudinal sections are separated by joints which extend wholly or partially through the walls of the shank'and which enable the sections to spread at the angle where the,

taper begins when therivet is upset.

In the form shown in Figs; 1 -4, the body of the rivet is formed from a blank having an integral center 6 which eventually forms the end of the rivet and the radial arms or strips a are broadened at a to form the flange. This blank is formed up as shown in Fig. 2, with a flange or head and a shank, the portion of the shank adjacentto the flange being cylindrical and-the portion ad-,

jacent to the end being slightly tapering. I

The integral end 6 is preferably indented or recessed as shown in Figs. 3 and 4. 2 A cap c is applied to the flanged head in the well known manner. Thus I have a rivetwith both ends closed, the point being indented and integral withthe strips which form the body of the shank.

' In Figs. 3 and 4 1 illustrate the means by which the rivet is crushed or upset and the manner in which the shank properly ex pands without crushing inwar Referring to Figs. 3 and 4:, e represents the anvil which is provided with boss 6' fitting into the indentation formed in the end of the rivet.

The follower (Z is connected to any suitable actuating means and, conforms to the shape of the head. The sheets of paper or other material to be fastened by the rivet are shown at 7.

As the follower descends, each of the strips which. form the body of the rivet tends to bend outward at the point of junction between the cylindrical portion and the tapering portion; This results from the fact that each strip makes a slight angle at a point where the taper begins, and since the thrust comes lengthwise of thestrip it tends to crush or give way outward and cannot crush in as it might do if it were perfectly straight. The body of the rivet spreads out as shown in Fig. 5 to form a bearing of considerable area which is forced against the under side of the paper The tendency of the sections to crush outward is increased by the action of the in- 110 i to force them outward.-

rivet. Such a rivet..would:crush in thesame By constructing my rivet .as I have de scribed I am enabled to upset it with very simple mechanism, to form the rivet closed at both ends and 'to make sure that it will alwaysexpand' outward and make a perfeet holding device. The rivet may be forced through the material to be fastened or inserted in a holepreviously made and it may be used: without the cap 0 if desired...

The indentmay be omitted from the tapering end or the. shank may be made cylindrical with the indentin theend but I prefer tocombine the two features as here shown, one supplementing the other in aiding in. the proper expansion of the shank. It will be seen that my rivet is capable of beingused with various thicknesses of material as it will crush more or less and will accommodate itself automatically tothe thickness of the material to be fastened. The section adjacentto the head may be formed otherwise than cylindrical so long as it makes'an angle with. the tapering end whereby the outward crushing; effect. is pro-. duced.

A hollow rivetzmay be made according to, my invention with. the. shank having integral tubular wallsby forming the rivet in the usual way. and scoring or cutting the walls; of the tube longitudinally. Such aconstruction isillustrated in Figs. 6 and v7, in which-is shown a rivet g formedwith integral walls and atapering end and scored at-gf to form, longitudinal stripsor sections extending over; the angles where the taper beginsandfor some distancein either direction toward the head and end ofxthe manner as; if. the; strips. were. entirely separatedas they Wouldbe separate atv the. angle where the outward bend takes place.

The. scoring or outtingonthelines gf may l extend only partially through the metal wall so long as it weakens the metal so that it gives way along;- these lines when .it is. crushed.

I claim 1.. A hollow rivet having a head "and hollow shank, said shank being composed of an integral end and longitudinal, strips integral with. said end and being formed with a tapering section at the end, making an angle with the body of the rivet, the longitudinal joints or spaces between said strips extending over or by said angle whereby, said angle. is made the bending point.

2. A hollow rivethaving a. .headand a hollow shank, said shank being; composed of an integral'indentedendi and longitudi:

nal strips vintegralwith. said end and 'being.

formed with a.tapering section at the end, making an angle. with the body of the rivet, the. longitudinalijoints or spaces between said stripseX-tending over or by said: anglev whereby. said angle is. made the bending point. i

3. A hollow rivet havinga head; anda hollow shank, said. shank being composed of longitudinal strips, and a. closed and indented end formed integral with said ,strips.

4. A hollow rivetghaving ahead anda hollow. shank, said wshank havingxa...closed-.

end, and a. tapering. section. at the; end

making an angle with the bodyof mama;

and being formed-with a. plurality oflongitudinal sections separated. by. longitudinal joints-extendingover orby; said angle and capable of givingway and. permitting the sections to bend. outward. at said angle, In testimony, whereof. I have afiixed my. signature, in presence of twowitnesses,

S. W. Barns Conn. 13.; Cnmcnrom Q'opi es 01f" this patent may-be obtained for-five cents e aoh by addressing-the Commissioner ojlatentsr Washing 12- c. 

